Protocol for the Provision of Amplification · Audiology and Speech-Language Pathology Act, 1991. All services for Amplification funded by the IHP shall be conducted exclusively by

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2014 Version 2014.01

Ontario Ministry of Children and Youth Services

Ontario Infant Hearing Program

November 17, 2014

Protocol for the Provision of Amplification

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Child Amplification Laboratory National Centre for Audiology Western University London, Ontario

CORRESPONDENCE

Marlene Bagatto, AuD, PhD Room 2262J Elborn College Child Amplification Laboratory National Centre for Audiology Western University London, ON, CANADA N6G 1H1 Voice: 519.661.2111 ext. 88949 Fax: 519.661.3805 Email: [email protected]

ACKNOWLEDGEMENTS

The evidence-based clinical protocol statements in this document are the responsibility of the Child Amplification Laboratory at the University of Western Ontario and detailed endorsement of any specific product or by any other person is not implied. The programmatic, process and outcome review, and contractual statements in this document are the responsibility of the Ministry of Children and Youth Services.

EDITORS Marlene Bagatto, AuD, PhD Susan Scollie, PhD CONTRIBUTORS Susan Scollie, PhD Marlene Bagatto, AuD, PhD Sheila Moodie, PhD Richard Seewald, PhD Martyn Hyde, PhD Stacey Weber, MSc Vanessa Martin, MSc Danielle Glista, PhD Anne Marie Tharpe, PhD Jeff Crukley, PhD Marianne Hawkins, PhD Charla Levy, MSc Sahar Zimmo, MSc Shane Moodie, MSc Frances Richert, MSc Vijay Parsa, PhD

mailto:[email protected]

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CONTENTS

CONTENTS ..................................................................................................................................................................... 3 SECTION 1: INTRODUCTION ........................................................................................................................................... 6

1.1 AMENDMENT HISTORY ........................................................................................................................................ 6

1.2 UPDATES TO THE PROTOCOL ............................................................................................................................... 6

1.3 FORECAST CHANGES ............................................................................................................................................ 7

SECTION 2: SCOPE.......................................................................................................................................................... 7 2.1 IHP CORE PRINCIPLES ........................................................................................................................................... 7

2.2 AMPLIFICATION GOALS ....................................................................................................................................... 7

2.3 AMPLIFICATION OBJECTIVES ............................................................................................................................... 7

2.4 TARGET IMPAIRMENTS ........................................................................................................................................ 7

2.5 AMPLIFICATION CANDIDACY ............................................................................................................................... 8

2.6 AMPLIFICATION PERSONNEL ............................................................................................................................... 8

2.7 NON-IHP AMPLIFICATION SERVICES .................................................................................................................... 8

2.8 SECOND OPINIONS .............................................................................................................................................. 8

2.9 INSTRUMENTATION, CALIBRATION & SUPPLIES .................................................................................................. 8

2.10 IHP PROTOCOLS & CASLPO GUIDELINES ............................................................................................................ 9

2.11 PROCEDURAL CONCERNS .................................................................................................................................. 9

2.12 DEVIATIONS FROM PROTOCOL .......................................................................................................................... 9

2.13 PERFORMANCE AUDITS ..................................................................................................................................... 9

2.14 TYPES OF ASSESSMENT ...................................................................................................................................... 9

2.15 TIMING OF AMPLIFICATION ............................................................................................................................. 10

2.16 INFECTION CONTROL STANDARDS .................................................................................................................. 10

2.17 CALIBRATION ................................................................................................................................................... 10

2.18 OTOSCOPY & CERUMEN/DEBRIS ..................................................................................................................... 10

2.19 AMPLIFICATION COMPONENTS ....................................................................................................................... 11

2.20 CLINICAL RECORDS & REPORTS ....................................................................................................................... 11

2.21 PERSONAL HEALTH INFORMATION ................................................................................................................. 12

SECTION 3: ASSESSMENT CONSIDERATIONS ............................................................................................................... 12 3.1 AUDITORY CHARACTERISTICS ............................................................................................................................ 12

3.2 CONSULTATION BY AN OTOLARYNGOLOGIST ................................................................................................... 12

3.3 ACOUSTIC CHARACTERISTICS............................................................................................................................. 12

3.4 RECD MEASUREMENT ........................................................................................................................................ 13

3.5 AGE-APPROPRIATE PREDICTED RECD VALUES ................................................................................................... 13

SECTION 4: SELECTION AND FITTING OF AMPLIFICATION ........................................................................................... 13 4.1 EAR IMPRESSIONS .............................................................................................................................................. 13

4.2 NON-ELECTROACOUSTIC CHARACTERISTICS ..................................................................................................... 13

4.3 ELECTROACOUSTIC CHARACTERISTICS .............................................................................................................. 13

4.4 DEVICE SELECTION ............................................................................................................................................. 14

4.5 OTHER ASSISTIVE TECHNOLOGY ........................................................................................................................ 14

SECTION 5: VERIFICATION OF AMPLIFCATION ............................................................................................................ 14 5.1 RECD VALUES ..................................................................................................................................................... 14

5.2 ELECTROACOUSTIC ANALYSIS ............................................................................................................................ 14

5.3 ELECTROACOUSTIC VERIFICATION ..................................................................................................................... 15

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5.4 APPLICATION OF ADVANCED TECHNOLOGIES ................................................................................................... 15

5.5 SIMULATED REAL-EAR MEASUREMENTS ........................................................................................................... 15

5.6 VERIFICATION STIMULI ...................................................................................................................................... 15

SECTION 6: INFORMATION AND INSTRUCTION ........................................................................................................... 16 6.1 ORIENTATION .................................................................................................................................................... 16

6.2 INFORMATION ................................................................................................................................................... 16

6.3 FAMILY SUPPORT ............................................................................................................................................... 16

SECTION 7: OUTCOME EVALUATION ........................................................................................................................... 16 7.1 FOLLOW-UP SCHEDULE ..................................................................................................................................... 16

7.2 FOLLOW-UP VISITS ............................................................................................................................................. 17

7.3 OUTCOME MEASURES ....................................................................................................................................... 17

SECTION 8: TRAINING AND CLINICAL DECISION SUPPORT .......................................................................................... 17 8.1 TRAINING REQUIREMENTS AND SUPPORT MECHANISMS ................................................................................ 17

8.2 IHP WEBSITE ...................................................................................................................................................... 17

SUPPLEMENT 1: PROGRAM CONTENT ........................................................................................................................ 18 S1.1 ONTARIO INFANT HEARING PROGRAM CORE PRINCIPLES .............................................................................. 18

S1.2 AMPLIFICATION OBJECTIVES ............................................................................................................................ 19

S1.3 TARGET IMPAIRMENTS .................................................................................................................................... 19

S1.4 INSTRUMENTATION, CALIBRATION & SUPPLIES .............................................................................................. 20

S1.5 DEVIATIONS FROM PROTOCOL ........................................................................................................................ 21

S1.6 PROCESS AND OUTCOMES REVIEW ................................................................................................................. 21

S1.7 TIMING OF AMPLIFICATION ............................................................................................................................. 21

SUPPLEMENT 2: ASSESSMENT CONSIDERATIONS ....................................................................................................... 23 S2.1 AUDITORY CHARACTERISTICS .......................................................................................................................... 23

S2.2 ACOUSTIC CHARACTERISTICS ........................................................................................................................... 24

S2.3 RECD MEASUREMENT ...................................................................................................................................... 24

S2.4 AGE-APPROPRIATE PREDICTED RECD VALUES ................................................................................................. 24

SUPPLEMENT 3: PRESCIPTION OF AMPLIFICATION ..................................................................................................... 25 S3.1 NON-ELECTROACOUSTIC CHARACTERISTICS ................................................................................................... 25

S3.2 ELECTROACOUSTIC CHARACTERISTICS ............................................................................................................ 26

S3.3 DEVICE SELECTION ........................................................................................................................................... 26

S3.4 OTHER ASSISTIVE TECHNOLOGY ...................................................................................................................... 26

SUPPLEMENT 4: INFORMATION AND INSTRUCTION ................................................................................................... 27 S4.1 ORIENTATION ................................................................................................................................................... 27

SUPPLEMENT 5: OUTCOME EVALUATION ................................................................................................................... 27 S5.1 OUTCOME MEASURES ..................................................................................................................................... 27

SECTION 9: REFERENCES .............................................................................................................................................. 28 SECTION 10: APPENDICES ............................................................................................................................................ 31

APPENDIX A: IHP INSTRUMENTATION ..................................................................................................................... 31

APPENDIX B: ESTIMATED HEARING LEVELS (EHLS) AND HEARING AID FITTING ..................................................... 33

APPENDIX C: COUPLING INSERT EARPHONES TO PERSONAL EARMOLDS ............................................................... 34

APPENDIX D: PROCEDURE FOR OBTAINING AN EAR IMPRESSION .......................................................................... 35

APPENDIX E: ELECTROACOUSTIC VERIFICATION ..................................................................................................... 37

APPENDIX F: INSTRUCTION AND INFORMATION ..................................................................................................... 38

SECTION 11: PROTOCOL ADDENDA ............................................................................................................................. 40 ADDENDUM 1: AMERICAN ACADEMY OF AUDIOLOGY PEDIATRIC AMPLIFICATION GUIDELINES .......................... 40

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ADDENDUM 2: FREQUENCY LOWERING HEARING AIDS ......................................................................................... 44

ADDENDUM 3: NOISE MANAGEMENT IN HEARING AID FITTING ............................................................................ 63

ADDENDUM 4: DECISION SUPPORT GUIDE FOR HEARING AID USE IN INFANTS AND CHILDREN WITH

MINIMAL/MILD BILATERAL HEARING LOSS ............................................................................................................. 78

ADDENDUM 5: MANAGEMENT OF INFANTS AND CHILDREN WITH UNILATERAL HEARING LOSS .......................... 90

ADDENDUM 6: REMOTE MICROPHONE HEARING ASSISTANCE TECHNOLOGIES .................................................... 96

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SECTION 1: INTRODUCTION

This Protocol addresses the provision of amplification ('Amplification') to infants and pre-school children registered

in the Ontario Infant Hearing Program (IHP). Providing amplification includes the process of prescribing a hearing

instrument based on appropriate assessment information, verification that the specified acoustical performance

targets have been achieved, and evaluation of device effectiveness in daily life.

Dispensing includes obtaining ear impressions for earmold fabrication, electroacoustic analysis of the prescribed

hearing instruments (ANSI test), adjustment of the hearing instruments to the settings provided, and hearing

instrument orientation.

This document addresses the provision of amplification (hereafter: 'Amplification') to infants and pre-school

children registered in the Ontario Infant Hearing Program (IHP). The document specifies context and procedures

for the provision of amplification, including specification of key procedures and equipment requirements.

Furthermore, several IHP Protocol addenda have been included. These addenda provide updates to evidence and

are intended to support current clinical practice within the IHP.

1.1 AMENDMENT HISTORY

This Protocol supersedes all previous provisions of amplification on subjects covered in this Document.

1.2 UPDATES TO THE PROTOCOL

With the recent amendments, several topics have been added or expanded based on current evidence and clinical

practice.

Date Document Title Amendment

October 2007 Ontario Infant Hearing Protocol for the Provision of Amplification Version 3.1

November 2014

May 2010 Ontarion Infant Hearing Program Outcome Measurement Protocol

Separate document (2010) www.dslio.com

April 2011 Ontario Infant Hearing Program Frequency-Lowering Hearing Aids Protocol Addendum and Support Document

November 2014

October 2013 American Academy of Audiology Pediatric Guidelines Summary and Support Document for the Ontario Infant Hearing Program

Minor changes. Included as Addendum 1 in this document

Topic Section

IHP Instrumentation Appendix A

AAA Guidelines Summary and Q&A Addendum 1

Frequency lowering technology Addendum 2

Noise management Addendum 3

Minimal/mild bilateral hearing loss Addendum 4

Unilateral hearing loss Addendum 5

Remote microphone hearing assistance technologies (FM) Addendum 6

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1.3 FORECAST CHANGES

We rely upon the accuracy of information contained in the Protocol. As such, any anticipated changes, omissions or additions may result in accordance with emerging research or recommendations.

Anticipated changes/additions:

a) Process and outcomes review b) Bone conduction hearing aid verification c) Updates to procedures to align with ANSI S3.46-2013

SECTION 2: SCOPE

2.1 IHP CORE PRINCIPLES

Amplification shall be provided in accordance with the IHP core principles of informed family/caregiver choice and

consent, timely provision of unbiased information based on the best available scientific evidence, and sensitivity to

family culture and values.

2.2 AMPLIFICATION GOALS

The main goals of Amplification are (i) to provide an amplified speech signal that is consistently audible across

levels, (ii) to avoid distortion of varying inputs at prescribed settings for the user, (iii) to ensure the signal is

amplifying sounds in as broad a frequency range as possible, and (iv) to include sufficient electroacoustic flexibility

to allow for changes in the required frequency/output characteristics related to ear growth or changes in the

auditory characteristics of the infant.

2.3 AMPLIFICATION OBJECTIVES

The specific objective of Amplification is to improve functional auditory capacity and participation in hearing- and

communication-specific situations. Published reports suggest that early improvement in hearing can facilitate the

development of sensory and perceptual skills, receptive and expressive language, speech production and literacy,

academic performance and social-emotional growth (Carney & Moeller, 1998).

2.4 TARGET IMPAIRMENTS

The nominal target permanent childhood hearing impairment (PCHI) includes any hearing threshold equivalent to

30 dB HL or greater at any frequency in the range 0.5-4 kHz, in either ear. The target PCHI includes conductive

impairment associated with structural anomalies of the ear but does NOT include impairment attributable to non-

structural middle ear conditions. The target PCHI also includes Auditory Neuropathy Spectrum Disorder (ANSD)

and retrocochlear disorders affecting the auditory brainstem.

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2.5 AMPLIFICATION CANDIDACY

For an infant to be considered a candidate for amplification, PCHI will have been identified through IHP audiologic

Assessment. The determination that amplification should be recommended on audiologic grounds is at the

discretion of the IHP audiologist. If amplification is indicated audiometrically, is elected by the family after review

of the options and information, and if absence of specific contraindications is confirmed by an otolaryngologist, the

process of Amplification shall be undertaken in a timely manner.

2.6 AMPLIFICATION PERSONNEL

The prescription of a hearing instrument is a controlled act that audiologists are authorized to perform under the

Audiology and Speech-Language Pathology Act, 1991. All services for Amplification funded by the IHP shall be

conducted exclusively by an audiologist registered with the College of Audiologists and Speech-Language

Pathologists of Ontario (CASLPO) who are also authorized by the IHP, having received approved training in this

Amplification protocol. Audiologists who prescribe hearing instruments for infants in this program shall be

registered prescribers with the Assistive Devices Program (ADP).

The dispensing of amplification within the IHP shall be completed by a dispensing audiologist who has been trained

in this protocol. Individuals who are registered dispensers with the ADP shall dispense hearing instruments to

infants in this program.

2.7 NON-IHP AMPLIFICATION SERVICES

Amplification services conducted by any person who is not an audiologist authorized by the IHP shall not be

funded by the IHP and shall not be deemed to provide a sufficient basis for subsequent management within the

IHP. Such services may be valid, but are not auditable by the IHP and therefore, full procedural compliance with

this protocol cannot be verified.

2.8 SECOND OPINIONS

Review of Amplification for ‘second opinion’ purposes shall not qualify for IHP funding, except with prior approval

of IHP management in individual cases. Second opinions may be requested by the IHP audiologist, the parents or

another IHP service provider if they believe that such a review may materially improve the accuracy or

effectiveness of the overall Amplification outcome. Specific procedures for intiating this request are outlined in a

procedural document that is not within the scope of this protocol (REF). Also, IHP audiologists may at any time

seek expert opinion from the designated provincial Centres of Excellence for this protocol, which are the Otologic

Function unit at Mount Sinai Hospital, Toronto, the Children’s Hospital of Eastern Ontario (CHEO), Ottawa, and the

National Centre for Audiology at the Western University, London.

2.9 INSTRUMENTATION, CALIBRATION & SUPPLIES

Amplification services shall be conducted only using equipment approved by the IHP, maintained according to IHP

specifications, and using operating supplies approved by the IHP.

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2.10 IHP PROTOCOLS & CASLPO GUIDELINES

All IHP audiologists shall practice IHP Amplification procedures in full compliance with the requirements of both

CASLPO and this protocol. IHP protocols may be more specific than CASLPO guidelines. Effort is made to ensure

that IHP protocols do not conflict with CASLPO guidelines. Such conflicts may arise inadvertently and if any IHP

audiologist perceives such a conflict, the CASLPO guideline shall apply. The audiologist shall notify Mount Sinai

Hosptial (Dr M Hyde) and/or The National Centre for Audiology at Western University (Dr M Bagatto) of the

conflict promptly and the IHP will act to resolve the issue at a provincial level.

2.11 PROCEDURAL CONCERNS

IHP Protocols are evidence-based to the extent possible. Evidence is reviewed by the IHP on an ongoing basis.

This may result in specification of procedures that differ from opinions in published journals. Every IHP audiologist

shall bring significant procedural concerns to the attention of MSH and/or the NCA. Substantive issues will be

addressed by new evidence review, re-examination of existing evidence, and/or provincial consensus

development. Changes to IHP protocols are outside the mandate of regional management and shall be authorized

ONLY by modification of the relevant IHP protocol document (such as this document), which shall govern IHP

provision of amplification throughout Ontario.

2.12 DEVIATIONS FROM PROTOCOL

Departures from this protocol may be appropriate in individual infants and under special circumstances. Their

nature and rationale shall be documented in clinical IHP case records. The IHP reserves the right to review

documentation and clinical records involving any such departures from this protocol, subject to consent from the

individual family affected and to Ontario’s personal health information and privacy legislation.

2.13 PERFORMANCE AUDITS

Every IHP audiologist who provides Amplification services funded by the IHP shall undergo process and outcomes

review periodically by the IHP, selected at random. It is a condition of continued audiologist authorization by the

IHP and continued procedural funding by the IHP that IHP Audiologists shall comply with the request to provide

the specified procedural and outcomes documentation. The IHP also reserves the right to conduct event-driven

process and outcomes review of individual IHP audiologists’ case records, as and when the need is determined by

the IHP. All provision of process and outcomes review materials shall conform to current provincial laws and

standards relating to personal health information.

2.14 TYPES OF ASSESSMENT

Assessments are ABR-based or Behaviour-based. The latter includes Visual Reinforcement Audiometry (VRA),

Conditioned Play Audiometry (CPA), or conventional audiometry. The choice of approach is at the discretion of the

IHP audiologist, taking account of the individual characteristics of the child and the context and purpose of the

Assessment. Both types can provide ear- and frequency-specific information that shall be used for the provision of

hearing instruments to infants within the IHP (see IHP Assessment Protocol).

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2.15 TIMING OF AMPLIFICATION

Where not medically contraindicated, the provision of Amplification to infants aged less than three months is at

the discretion of the IHP prescribing audiologist, but is not generally recommended by the IHP. Many factors must

be weighed when considering at what age to provide amplification. The IHP fully endorses the prescription and

verification of amplification by six months of age, as recommended by the US Joint Committee on Infant Hearing

(JCIH, 2007). Delay that will compromise that objective must be avoided wherever possible. However, there is

negligible scientific evidence of relative benefit from fitting earlier than three months of age, and what evidence

there is about intervention timing suggests that six months of age is sufficiently early to accrue full benefit.

2.16 INFECTION CONTROL STANDARDS

All Amplification services shall comply with all pertinent standards of the facility relating to infection control. In the

absence of specific facility standards, generally accepted standards shall apply.

2.17 CALIBRATION

The IHP audiologist shall perform at least weekly calibration of their hearing instrument test systems. These

systems shall also be calibrated on an annual basis, as scheduled by the facility or the regional IHP.

2.18 OTOSCOPY & CERUMEN/DEBRIS

Cursory otoscopy shall be conducted at the start of any IHP Amplification appointment. Its main purpose is to

detect foreign bodies, canal occlusion and any physical condition of the ear that indicates referral to physician.

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2.19 AMPLIFICATION COMPONENTS

Wherever feasible, provision of Amplification shall include at least ALL of the following:

A complete description of the infant’s

auditory characteristics for both ears;

Consultation by an otolaryngologist;

A description of the acoustic characteristics

of the infant’s ear canal(s) in the form of a

Real-Ear-to-Coupler Difference (RECD);

Accurate ear impression(s) for the purposes

of fabricating an earmold;

An assessment of the non-electroacoustic

needs of the infant;

Electroacoustic analysis of prescribed

hearing instruments (ANSI test);

DSL m[i/o] v5 target ear canal sound

pressure levels (SPL) for the amplified long-

term average speech spectrum;

DSL m[i/o] v5 target ear canal SPLs for

defining the maximum saturation response

of the hearing instrument;

DSL m[i/o] v5 target ear canal SPLs for soft

and loud speech;

Verification that the electroacoustic

characteristics of the hearing instrument

adequately match the auditory needs of the

infant. For the target population, simulated

measurements of the real-ear aided

response (REAR) must be completed across

test levels for speech and maximum output;

Instruction and counseling sessions with the

parent/caregiver when the hearing

instrument is first fitted and at subsequent

follow-up visits as needed;

An evaluation of the outcome of the

intervention;

Appropriate follow-up schedule and

adjustments to the amplification as require

2.20 CLINICAL RECORDS & REPORTS

All Amplification records shall be maintained in a manner satisfying both CASLPO and the IHP. The Amplification

records shall be maintained in hardcopy and, for programmable hearing instrument settings, in data files. The

infant’s audiological record should include details of the procedure used to calculate prescriptive targets (i.e. RECD

values, DSL targets), a summary of the prescribed amplification including the settings of the device, make and

model, earmold specifications, and a synopsis of recommendations and information provided to the

family/caregiver. It is also important to note progress that the infant is making with the amplification devices. The

records must be fully sufficient to demonstrate compliance with the required elements of the IHP Amplification

protocol, given a performance review. They should also be sufficient to facilitate consultative, clinical review and

case conferencing.

The audiologist shall complete the appropriate IHP Amplification summary report forms and send them to the local

IHP coordinating agency in a timely manner. If completion of the provision of Amplification requires a further

appointment that is feasible promptly, the report may be deferred to follow the ensuing appointment.

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2.21 PERSONAL HEALTH INFORMATION

Management of all personal health information arising from the Amplification process shall comply with all current

legislation of the Government of Ontario.

All transmission of personally-identifiable information shall be consented by the appropriate family member or

authorized caregiver. All transmission of individual case information by fax, hardcopy or email, such as for IHP

training follow-up, internal clinical decision support or IHP audit, shall be rendered non-identifiable.

Local computer storage of identifiable and interpretable health information must take account of current Ontario

guidelines in relation to unathorized access, theft or loss.

SECTION 3: ASSESSMENT CONSIDERATIONS

3.1 AUDITORY CHARACTERISTICS

Auditory characteristics shall be defined prior to providing amplification to infants within the IHP. Threshold

estimates for at least 500 and 2000 Hz shall be obtained in each ear prior to initiating the provision of

amplification. Threshold estimates at other frequencies (i.e. 1000 and 4000 Hz) are recommended, but not

required for the provision of amplification. Strategies for determining hearing thresholds will vary depending on

the age of the infant.

3.2 CONSULTATION BY AN OTOLARYNGOLOGIST

Where amplification is indicated and elected by the family, referral leading to review by an otolaryngologist is

required in order to confirm that non-medical intervention is appropriate. This may occur during the same consult

for the etiologic investigation of the PCHI. Provided the otolaryngologist establishes the absence of medical

contraindications to amplification, the audiologist is free to proceed with the provision of amplification for the

infant.

In the IHP context, an assessment by an otolaryngologist shall be recommended to the child’s primary care

physician whenever the IHP Audiologic Assessment reveals PCHI. That referral has the main goal of a broad review

of the child’s health status in light of the hearing impairment, and may include radiologic, serologic, and

ophthalmologic tests, as well as genetic review and other cross-referrals.

3.3 ACOUSTIC CHARACTERISTICS

The Real-Ear-to-Coupler Difference (RECD) measurement procedure was developed to determine an individualized

acoustic transform for use with the Desired Sensation Level (DSL®) Method (Moodie et al., 1994; Seewald, 1995;

Scollie et al., 2005). The individual’s RECD is used to obtain SPL thresholds, generate the appropriate gain and

output response for a hearing instrument, and has been shown to be highly repeatable and valid (Munro & Hatton,

2000; Sinclair et al., 1996; Seewald et al., 1999). Therefore, it is a required element in the Amplification process

for infants involved in the IHP.

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3.4 RECD MEASUREMENT

Wherever feasible, IHP audiologists shall measure the individual infant’s RECD as part of the Amplification process.

RECD measurements should be obtained from each infant using an IHP approved real-ear hearing instrument test

system (see Appendix A) following the procedure described by Moodie et al (1994). RECD values, tester, coupling

type (earmold, foam tip, immittance tip), ear and test date shall be documented and retained on file.

3.5 AGE-APPROPRIATE PREDICTED RECD VALUES

In the event that the individual RECD measurement cannot be obtained, age-related predicted values shall be

applied. The predicted values used shall be specified (i.e. age, coupling type), documented, and retained on file.

The current values are derived from data collected from infants and children of varying ages and are provided for

foam tip and earmold coupling (Bagatto et al, 2002).

SECTION 4: SELECTION AND FITTING OF AMPLIFICATION

4.1 EAR IMPRESSIONS

Ear impressions will be obtained from each ear for fabrication of personal earmolds (see Appendix D and CASLPO

PPG, 2013) as per the earmold prescription. The prescription shall include length of canal and helix, material

(silicone, etc.), tubing type, shell style, vent (if possible) and options. Some earmold modifications will be limited by

the size of the infant’s ear, and any difficulty meeting the requirements of the prescription should be referred back

to the prescribing audiologist.

The infant’s earmolds should be made of a soft material for comfort, safety and retention. Also, softer material

reduces the possibility of acoustic feedback from the hearing instrument. The advantages and disadvantages of

various earmold materials should be weighed for each individual infant (See Appendix D for details). The cost and

need for frequent replacement of earmolds to prevent acoustic feedback should be explained to the

parent/caregiver.

4.2 NON-ELECTROACOUSTIC CHARACTERISTICS

The audiologists shall consider non-electroacoustic characteristics of the prescribed hearing aid. The style of the

hearing aid, monaural vs binaural fitting, deactivation of advanced features, FM system compatibility, and tamper

resistant battery doors are important considerations when providing hearing aids to infants and young children.

4.3 ELECTROACOUSTIC CHARACTERISTICS

The use of a systematic, objective approach to electroacoustic selection that incorporates age-dependent variables

into the computations for selecting a hearing instrument is required. The formula that shall be used to develop the

appropriate electroacoustic characteristics for each infant involved in the IHP is the Desired Sensation Level

Method m[i/o] v5 (Scollie, et al. 2005) included within IHP approved real-ear hearing instrument test systems

(Appendix A). DSL v5 provides targets that vary depending on the type of fitting. Specifically, targets for pediatric

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patients (i.e. congenital hearing loss) and for adult patients (i.e. acquired hearing loss). This change was based on

evidence for adult-child differences in performance ceilings, loudness ratings, and preferences by listening level

(see review in Scollie et al, 2005). For the purposes of the IHP, clinicians shall use the DSL m[i/o] v5 ‘Child’ targets

within the real-ear hearing instrument test system. Coupler targets for the amplified long term average speech

spectrum and MPO across frequency for each ear requiring amplification shall be documented.

4.4 DEVICE SELECTION

Once the non-electroacoustic and electroacoustic characteristics of the potential hearing instrument have been

identified, the audiologist shall select a hearing instrument that will meet the criteria. Earmolds and hearing

instruments shall be ordered, with a request for pediatric filtered earhooks.

4.5 OTHER ASSISTIVE TECHNOLOGY

Some infants may be candidates for assistive listening technologies and devices other than personally-worn

hearing instruments. If the IHP audiologist determines that the infant is a candidate for other assistive technology,

such as a remote microphone hearing system (e.g,. FM/DM system), the audiologist shall explain the option to the

family and facilitate careful consideration and informed choice. If the device option is elected by the family, the

audiologist shall provide the appropriate prescription to the parents, and/or facilitate access to service provision,

as soon as is appropriate. Further information about the selection and verification of remote microphone hearing

assistance technologies can be found in Addendum 6.

SECTION 5: VERIFICATION OF AMPLIFCATION

5.1 RECD VALUES

The acoustic properties of the infant’s personal earmold shall be taken into account through the use of RECD

measurements or age-appropriate predicted values (see sections S2.3 and S2.4 of this document). Whenever a

new earmold is obtained, a new RECD measurement shall be collected and applied in the calculation of

prescriptive targets. Thus, the prescriptive targets shall be updated with the new RECD measurement when a new

earmold is obtained. The verification procedures described in this document shall be carried out every time the

prescriptive targets have been updated.

5.2 ELECTROACOUSTIC ANALYSIS

Upon receipt of the hearing instruments from the manufacturer, the dispenser shall proceed with an

electroacoustic analysis of the hearing instruments (ANSI 1996) to confirm that the hearing instruments are

functioning according to the manufacturer specifications. Any departure from the specification of gain, output, or

distortion at any frequency beyond acceptable tolerances should be reported back to the manufacturer and the

hearing instrument returned for repair or replacement as appropriate. A biological listening check should also be

performed to subjectively evaluate sound quality and physical function of components.

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5.3 ELECTROACOUSTIC VERIFICATION

The prescribed hearing instrument shall be adjusted to approximate the target electroacoustic values for gain and

maximum output that were specified according to the section of this document dealing with Prescription. All

verification curves, in SPL, and final hearing instrument settings shall be documented and dated for each ear

requiring amplification. Ideally, real ear measurements of gain and maximum output values should be performed

on each ear (i.e., the RECD may have already been measured in the pre-selection phase) and the hearing

instrument adjusted to provide the best match to targets. With the infant population, it is difficult to obtain valid

and reliable measures of real-ear hearing instrument performance using this method. Therefore, predicting the

real-ear performance of the hearing instrument using the infant’s RECD is the preferred method for infants. This

approach is fully implemented through the use of DSL within approved real-ear hearing instrument test systems.

For a detailed description of this procedure see Appendix E. One major advantage of this approach is that shaping

the electroacoustic response of the hearing instrument can be performed in a highly controlled hearing instrument

test box environment. Additionally, the infant does not need to be present for fine tuning adjustments made at

this stage. It is, however, important for the clinician to check for feedback from the instrument once it has been

placed on the infant’s ear.

5.4 APPLICATION OF ADVANCED TECHNOLOGIES

Automatic feedback suppression technologies should be employed if feedback is noted when the hearing

instrument has been placed on the infant’s ear following verification. Every attempt to reduce feedback (i.e. good

earmold fit, use of lubricant) should be attempted prior to applying feedback suppression strategies. If applied,

verification of the instrument shall be conducted following application of these technologies. The application of

feedback reduction should be reassessed whenever new earmolds are obtained, and the feedback suppression

technology should be deactivated when not required.

Advanced signal processing, such as automatic noise reduction, automatic program switching, and frequency

lowering processors, are continuously evolving. As new technologies and new evidence emerge, IHP clinicians are

encouraged to use technologies that meet the listening needs of their patients. Specific evidence review and

protocols have been developed for frequency lowering, noise management, and remote microphone hearing

assistance technologies (Addendum 2, Addendum 3, Addendum 6).

5.5 SIMULATED REAL-EAR MEASUREMENTS

With the infant population, it is difficult to obtain valid and reliable measures of real-ear hearing instrument

performance using real-ear measurement procedures. Therefore, predicting the real-ear performance of the

hearing instrument using the infant’s RECD is the preferred method for infants and young children. Simulated

measurements of the real-ear aided response (REAR) shall be conducted for each ear requiring amplification

through the use test box measurements within real-ear hearing instrument test systems. These procedures are

outlined in Appendix E.

5.6 VERIFICATION STIMULI

Verification of hearing instrument performance across input levels in the range of 55 to 75 dB SPL shall be

conducted to determine the audibility and compression characteristics of the instrument. Verification of speech

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targets shall be completed using pre-recorded, calibrated speech test signals. Maximum output characteristics for

most hearing instruments shall be verified using narrowband stimuli at a high test level (85 to 90 dB SPL).

SECTION 6: INFORMATION AND INSTRUCTION

6.1 ORIENTATION

The dispensing and fitting of an instrument shall include explanations of use, care and maintenance of the devices

provided in an understandable way and preferably supplemented by appropriate printed materials. Infants are

unable to report if their hearing instruments are malfunctioning, so family vigilance is required and a care kit must

be provided (see S5.1). Supportive information and instruction for the family/caregiver shall be given at the time of

the first fitting of the hearing instrument, and at follow-up visits.

6.2 INFORMATION

In any communication with families, the principles of the IHP should be reflected. Only evidence-based information

should be imparted. Anecdotal information and personal opinions are not considered appropriate content for

communication with parents. Service providers are encouraged to impart unbiased information in their area of

expertise. Interdisciplinary referrals should be made when appropriate as questions arise which are outside of the

prescriber’s/dispenser’s scope of practice such as prognosis, or medical issues.

6.3 FAMILY SUPPORT

Despite their decision to proceed with amplification, families may continue to need various supports to help them

through the process of acceptance and adaptation. Psychological support is available through the local IHP Family

Support Worker, but it is not the role of such personnel to provide information on audiological matters. A

combination of timely and relevant information from the IHP Audiologist, written materials provided by the IHP,

and psychological support from Family Support Personnel is the desired minimum.

SECTION 7: OUTCOME EVALUATION

7.1 FOLLOW-UP SCHEDULE

Follow up to the initial hearing instrument fitting should be accomplished on a regular schedule, with

accommodation for individual needs. The Amplification Audiologist should see the infant and family for a minimum

number of 2 follow up visits within the trial period which is recommended to be a minimum of 60 days. A schedule

of follow-up visits thereafter shall include visits about every three months for one year after the fitting of

amplification, about every six months for a second year, and annually thereafter until grade one entry. This follow-

up schedule is typical but may vary from infant to infant. Some may require less frequent visits, but for infants

identified as having a progressive or fluctuating hearing loss or auditory neuropathy spectrum disorder, the regular

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schedule is especially important. The schedule should be re-assessed on an ongoing, individual basis, with

appropriate documentation.

7.2 FOLLOW-UP VISITS

At each follow-up visit, an incremental history shall be obtained from the family. Use, care and maintenance of the

hearing instruments should be discussed as parents’ questions arise, or as re-instruction is required. Otoscopy,

middle-ear analysis, and assessment of hearing levels (typically behaviour-based) shall be done (see IHP

Assessment Protocol). Earmolds shall be assessed for appropriate fit and new earmolds obtained when required.

An RECD should be re-measured to account for growth and development, as well as if the earmold has changed or

if there has been a change in middle ear status. Subsequent adjustments should be made to the hearing

instruments as needed.

7.3 OUTCOME MEASURES

Validation of the fitting shall be done using procedures outlined in the IHP Outcome Measurement Protocol (2010)

which is provided in a separate document (Bagatto et al, 2011 ).

SECTION 8: TRAINING AND CLINICAL DECISION SUPPORT

8.1 TRAINING REQUIREMENTS AND SUPPORT MECHANISMS

All audiologists wishing to provide IHP Amplification services shall have received training in this protocol that is

approved by IHP. The IHP training sites are Mount Sinai Hospital (MSH), Toronto as well as the Children’s Hospital

of Eastern Ontario (CHEO), Ottawa for ABR-based and VRA-based Assessments and Western University, London for

VRA-based Assessments and IHP Amplification protocols.

At any time, audiologists may fax records to Western University for a clinical or procedural opinion regarding

Amplification. An email to [email protected] shall accompany the fax and all records shall be completely de-

identified. Audiologists are encouraged to do this if significant difficulties arise in completing the IHP protocol. This

is a funded part of IHP quality management.

Audiologists may receive additional training or procedural review, by application to the Ministry of Children and

Youth Services.

8.2 IHP WEBSITE

A website supporting the IHP has been developed at Mount Sinai Hospital. The URL is

http://www.mountsinai.on.ca/care/infant-hearing-program/health-professionals. All IHP protocols and many

related materials are available on the website.

http://www.mountsinai.on.ca/care/infant-hearing-program/health-professionals

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SUPPLEMENT 1: PROGRAM CONTENT

S1.1 ONTARIO INFANT HEARING PROGRAM CORE PRINCIPLES

The IHP is a program of the Early Years Branch of Ontario’s Ministry of Children and Youth Services (MCYS). It was

implemented throughout the province in 2002 and is an example of an Early Hearing Detection and Intervention

(EHDI) program. A better descriptor, recommended by the Public Health Agency of Canada’s Canadian Working

Group on Childhood Hearing (CWGCH, 2005), is an ‘Early Hearing and Communication Development’ (EHCD)

program. The IHP includes UNHS (Ontario’s birth rate ~ 130,000/y), surveillance of high-risk infants,

comprehensive audiologic assessment, family support services, linkage to medical services, provision of assistive

technologies, and a range of services and other linkages to enhance the development of language and early

literacy.

The core values of the IHP are that service provision should be family-centered, with fully informed

family/caregiver (hereafter ‘family’) choices based on unbiased information that is grounded in the best available

scientific evidence. 'Family-centered' means that the family’s choices are paramount and that their culture, values

and preferences must be respected. The family should be the fullest possible partner in the development of an

individualized pattern of required services. The family must be assisted in making choices among service options

on the basis of information that is valid, timely, comprehensible, relevant, complete and unbiased. Interactions

among IHP service providers and families must reflect these core program values and also must be consistent with

documentary information for both families and professionals that is provided by the program.

During their path through the IHP, families will be provided with brochures and other information about program

rationale, procedures, significance of outcomes, and options for actions. This is available in all the languages most

frequently represented in Ontario. Families shall be encouraged to consider the evidence carefully in arriving at

their choices. In all materials supplied by the IHP, both for families and for professionals, areas in which there is a

lack of sound, scientific evidence will be identified. Standard, published methodologies of Evidence-Based Practice,

including systematic and semi-systematic reviews will be used on an ongoing basis to evaluate and update

scientific evidence.

Audiologists will use equipment that meets the criteria established by the Ministry.

To justify the resource expenditure required by such a universal program, and also on ethical grounds, there is a

need to achieve the highest possible service quality and consistency throughout Ontario. Accordingly, core

program components such as audiologic assessment (‘Assessment’) must follow well-defined, evidence-based

procedural standards. Many of the Assessment elements are mandatory and are required practice to qualify for

IHP funding. Other procedures are recommended but not required, and in yet other areas there may be

insufficient evidence even for a recommendation. The IHP acknowledges that individual infants and special

circumstances of testing may require clinical judgment and adaptations of standard procedures. When the

program standard of care is not followed, a documented rationale for the departures may be required by the IHP.

This document addresses Assessment of infants registered with the IHP. The contents are based on: (i) workshops

for Ontario audiologists dating from December 2000 to the present (ii) numerous and ongoing reviews of scientific

and clinical literature, (iii) ongoing protocol reviews and consultations with leading experts worldwide, (iv)

extensive experience with tonepip ABR and other pediatric audiometric procedures, in Ontario, over a period of

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more than two decades, (v) feedback from program professionals, and (vi) policy and procedural developments

initiated by the Ministry of Children & Youth Services.

The clinical protocol itself is based on current evidence about effectiveness and efficiency of specific procedures.

Therefore, it will evolve. In some areas, current evidence is incomplete and interim decisions have been made.

The IHP will continue to evaluate its operations and outcomes, as well as continue to assess new clinical

technologies and published scientific data. Revisions or addenda to this document will be issued as required.

Key sources for some components of this protocol are listed in the reference section of this document.

S1.2 AMPLIFICATION OBJECTIVES

This document addresses the Provision of Amplification for infants registered in the Ontario Infant Hearing

Program (IHP). Most infants requiring amplification will have been identified with the IHP target permanent

childhood hearing impairment (PCHI) through universal newborn hearing screening. These infants will typically

have received Audiologic Assessment within the first three months. A minority will have been identified by repeat

screening of at-risk infants or by other referral routes, and will have received Assessment in order to be eligible for

IHP services prior to school entry at grade one. See the companion document ‘Audiologic Assessment Protocol,

version 3.1, January 2008’ for the details and rationale of the IHP Assessment protocol.

The Provision of Amplification, as described in this document, is a process that includes the calculation of

prescriptive targets based on assessment information, the selection of the physical and electroacoustic elements

of a hearing instrument, verification that the specified acoustical performance targets have been achieved, and

evaluation of device effectiveness in daily life. The prescription shall include a specification of the type of hearing

instrument and earmold to be fitted, appropriate settings and applications that will result in an amplification

system that addresses the needs of the individual infant and family.

For the purposes of this document, a ‘hearing instrument’ is defined as any electronic device fitted to the ear or

skull and designed to amplify and deliver sound to the ear. These devices include, but are not limited to, hearing

instruments that are body-worn, behind-the-ear, in-the-ear, in-the-canal, completely in the canal, BICROS, CROS,

and bone conduction (including BAHA Softband).

The goals of Amplification are to improve the ability to hear and thereby to facilitate the development of sensory

and perceptual skills, receptive and expressive language, speech production and literacy, academic performance

and social-emotional growth (Carney & Moeller, 1998).

This document defines the standard of care for Provision of Amplification within the IHP context, and provides a

guiding framework for clinical practice. It defines key, mandatory and discretional elements of the protocol and

gives their underlying rationale. The procedures described are designed to provide audiologists with protocols for

providing hearing instruments to infants as part of a comprehensive plan for facilitating communication

development.

S1.3 TARGET IMPAIRMENTS

The IHP target impairment set includes any PCHI for which there is satisfactory evidence that it will compromise

auditory development and speech perception, in the absence of intervention. The target disorder includes

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puretone threshold elevation to a level equivalent in an adult to 30 dBHL or greater at any frequency in the range

0.5 to 4.0 kHz.

Currently, there is no compelling scientific evidence that lesser severities of impairment merit address by public

health programming, but that issue is the subject of current research. Globally, some programs limit their targets

to hearing levels that are 40 dBHL or greater in the better ear. Yet, from first principles of psychoacoustics it is

clear that such a conservative criterion will fail to address many children with a substantive limitations of

perceptual function.

Hearing impairment is considered ‘permanent’ by the IHP if it is irreversible by medication or surgery or if it is likely

to sustain for a period of six months or more. This includes most impairment of sensory or neural origin, as well as

conductive impairment with a ‘structural’ cause such as ear canal or middle-ear agenesis or dysgenesis.

It is appropriate to include in the IHP target definition children with unilateral PCHI because: (i) they are at risk for

bilateral PCHI, (ii) they are at risk for increased disability should the normal ear acquire a conductive disorder, even

if transient, and (iii) specific strategies are indicated to enhance hearing and/or communication development in

such children. Support for managing unilateral PCHI can be found in Addendum 5 of this document.

The IHP target also includes the cluster of disorders commonly termed ‘Auditory Neuropathy’ (AN). This is referred

to within the IHP as Auditory Neuropathy Spectrum Disorder (ANSD) on the grounds that (i) many such cases may

not have genuine neuropathy, as commonly defined neurologically ,(ii) communication of an etiologically and

pathophysiologically specific diagnosis such as ‘neuropathy’ is an act that is restricted in Ontario to physicians, and

(iii) ‘Auditory Neuropathy Spectrum Disorder’ is a legitimate, non-etiologic descriptor of an auditory system

dysfunction that may include abnormal quantity and/or temporal distribution of afferent neural activity in varying

degrees.

ANSD is included in the target because it may be present in up to 10% of infants with pre-lingual PCHI and because

even if there is negligible loss of hearing sensitivity, there is likely to be a significant disorder of speech perception,

mediated by inadequate coding of rapid stimulus events.

Transient hearing disorders such as threshold elevations due to middle ear fluid and/or infection are NOT targeted

by the IHP. Such disorders are the domain of the well-established, universal medical care system in Ontario

(funded by the Ontario Health Insurance Plan, OHIP). The IHP is NOT an alternate system for audiometric services

in the context of active medical or surgical management of conductive hearing disorders.

S1.4 INSTRUMENTATION, CALIBRATION & SUPPLIES

Audiologists will use the equipment that meets the criteria established by the IHP. Current IHP instrumentation

requirements are listed in Appendix A.

Routine calibration checks of real-ear hearing instrument test systems are necessary for appropriate operation of

the system and shall be completed by the audiologist. Yearly calibration services will be arranged by each lead

agency and/or by the lead agency’s subcontracted partners, with reasonable notice to the Amplification centres.

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S1.5 DEVIATIONS FROM PROTOCOL

The IHP recognizes that special circumstances may indicate departures from some (but not all) of the procedures

specified in this protocol. Such departures are at the discretion of the IHP audiologist. This does not mean that this

protocol is generally discretional. IHP funding for procedures is conditional upon specific deliverables in terms of

quantity, quality and effectiveness, as defined in this and other protocols. Every reasonable effort must be made to

comply with IHP protocols, in the interest of quality of care, consistency of care (equity), and evaluability of overall

program performance and outcomes. The evaluation requirement imposes a need for comprehensive and

standardized documentation and clinical record-keeping. In addition, all significant deviations from this Protocol

shall be documented so as to permit independent review of their nature and the validity of their rationale.

S1.6 PROCESS AND OUTCOMES REVIEW

Protocol compliance will be evaluated routinely by several mechanisms, including chart review of IHP Audiologists,

with random selection of who will be reviewed.

It was established at the outset of IHP protocol development that periodic performance audit was necessary and

appropriate. The agreed process is intended to enhance program quality and to facilitate Audiologists’

understanding of, and compliance with, IHP mandatory procedures in a collaborative manner.

The audit includes detailed review by designated IHP expert assessors of clinical records and reports for a sample

of case records, including records specified by IHP management and records elected by the audiologist.

Assessment performance is evaluated and assigned a rating of compliance. Compliance that is less than complete

is addressed in confidence with the auditee by the expert assessor, by several support mechanisms including

additional training as required. Continued entitlement to conduct IHP Assessments is conditional upon the

evaluation by the designated expert assessor(s).

As well as the routine Audit schedule, event-driven Audits of specific audiologists may be initiated by the IHP when

it is deemed necessary in the interests of children and families. If concerns arise about the performance of any IHP

audiologist in reference to any child receiving services funded by the IHP, the concern shall be raised with the local

coordinator, who shall request an event-driven quality Audit. This internal IHP process has no relationship to any

peer review or disciplinary process specified by CASLPO. Any communication with CASLPO shall be at the discretion

of the IHP auditor(s).

S1.7 TIMING OF AMPLIFICATION

There are several concerns that must be taken into account when considering providing amplification to an infant

less than three months of age. For example, the first three months of life is a period of plasticity and rapid change

in the acoustical and physical properties of the external meatus. This can cause difficulty in achieving a satisfactory

and stable earmold fit, and may necessitate many follow-up visits for adjustment. Rapid anatomical maturation

coupled with small and diverse canal volumes in neonates affect real-ear SPLs and have implications for the

accuracy of prescriptive parameters based on group norms as well as for the stability of real-ear measures over

time. There is also rapid maturation of both the middle ear and the afferent auditory pathways, and these may

cause changes in hearing as well as increase the possibility of audiometric error.

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The process of prescribing, ordering, supplying, and verifying a hearing instrument, and accounting for scheduling

of appointments, mold and instrument adjustments and various other possible delays, may take two months or

more. The IHP interpretation of the JCIH recommendation is not prescription of a hearing instrument at six months

but a completed process of prescription, verification and adjustment, if necessary, by six months. This timeline

may require that the hearing instrument evaluation appointment should typically occur by four months of age,

which in turn may mean that the Assessment and review by an otolaryngologist should be completed by about

three months, wherever possible. This is reasonably consistent with initiating the Assessment process by about

two months. Of course, factors such as illness, active middle ear disorders or audiometric uncertainty may cause

significant delays in successful provision of amplification.

From these considerations, it is anticipated that the majority of IHP Amplification activities will occur in infants

aged about 3-6 months. This is reasonably consistent with published data from large UNHS programs, but is itself

an ambitious target in the population of NICU graduates. A minority of infants will arrive at Amplification after 6

months of age; these represent infants identified by UNHS but for whom provision of amplification was delayed, as

well as infants with confirmed hearing impairment following at-risk repeat screening or referral.

Infants who have bilateral PCHI of moderate or greater degree are unequivocally candidates for binaural

amplification, unless there is a clear, documented contraindication. It is emphasized that candidacy here means

audiometric candidacy, and that the first outcome of candidacy determination by the audiologist is a

recommendation that the family consider carefully the evidence for the amplification option, among other options

that may be available locally. Should a delay in the provision of amplification occur due to the family’s

participation, or lack thereof, in the process, and/or due to illness in the child, it should be fully documented by the

IHP audiologist.

Within the IHP, infants with a PCHI of lesser severity but of at least 30 dBHL are also considered candidates for

amplification and/or personal FM systems. Evidence suggests that infants with this degree of hearing impairment

are at risk for experiencing academic difficulty (Bess, Dodd-Murphy, & Parker, 1998; Bess and Tharpe, 1984; Wake

et al, 2004). A decision support guide for managing infants with minimal/mild bilateral hearing loss can be found in

Addendum 4. Infants identified with a unilateral PCHI may be candidates for amplification. Evidence suggests that

amplification recommendations be based on the level of hearing loss in the affected ear. Further detail is described

in Addendum 5. Infants who have been identified as having ANSD, and where behavioural data exist, may be fitted

with amplification at the discretion of the IHP audiologist, should the family elect it. Infants who have been

identified as having ANSD based on ABR findings should be evaluated behaviourally before amplification is

considered. Individuals with ANSD have been shown to have variable thresholds (i.e. range from normal to

profound) which cannot be determined by ABR alone (see Assessment Protocol).

Infants in which no response by ABR is determined shall not exclude the individual from being considered a

candidate for amplification. Residual hearing may exist at levels greater than the ABR system is capable of eliciting

and the infant may still experience benefit from hearing instruments. Severe to profound hearing impairment is

included as part of the candidacy criteria for cochlear implantation.

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SUPPLEMENT 2: ASSESSMENT CONSIDERATIONS

S2.1 AUDITORY CHARACTERISTICS

For infants under six months of age and for some older infants, Assessment is based on objective, physiologic

measures, mainly but not exclusively on tonepip ABR. It is usually possible to obtain accurate, frequency-specific,

ear-specific puretone threshold estimates by such measures. In most cases, tonepip ABR can provide audiometry

that is sufficient to fully inform communication development services, including amplification. When the IHP

Assessment protocol is followed, then unless there is a specific indication of unreliability of ABR findings (such as a

finding of ANSD or fluctuating conductive impairment), it is not consistent with IHP goals and objectives to defer

communication development options (where elected by the family) pending ‘behavioural confirmation’ of ABR-

based threshold estimates. As described in the Assessment Protocol, the ABR-based threshold estimates are

referenced in estimated hearing level (eHL). This represents a behavioural threshold derived from ABR-based

estimates. The hearing instrument prescription must be calculated using the eHL data obtained during the

assessment (Bagatto et al, 2005). Further information about this application can be found in Appendix B.

For children over the age of six months, visual reinforcement or play audiometry is appropriate and will provide

ear- and frequency-specific information. Auditory characteristics for this age group must be defined following

procedures outlined in the IHP Assessment protocol.

The availability of frequency-specific threshold data is important for the prescription of amplification. If the

presence of PCHI has been confirmed, the process of amplification may proceed on the basis of ear-specific

threshold estimations at 500 and 2000 Hz. Delay in the process pending the mandatory collection of thresholds at

1000 and 4000 Hz is not warranted at this stage. There will be cases where full audiometric information beyond

500 and 2000 Hz is not available. In these instances, the clinician must make a best estimate, based on the

thresholds provided as well as additional clinical and/or familial information, of the residual hearing across the

frequency range important for speech.

For infants in whom no response is indicated on the ABR and ANSD is presumed absent, amplification should be

provided cautiously. The following procedure is recommended:

1. If no response (NR) was indicated on the ISCIS Assessment form, consult with the Assessment Audiologist

to determine the highest level (dB nHL) that was presented at each frequency in each ear during the ABR.

2. Apply the frequency-specific correction to that level (see Assessment Protocol) to obtain a corrected

threshold in eHL.

3. Subtract 5 from the resulting eHL if the threshold search was conducted using 10 dB step sizes. If 5 dB

step sizes were used, skip Step 3.

In such cases, continued observation and assessment of the infant are especially important.

Audiologic Assessment of an infant with PCHI is not an event, but a process. Even if complete and apparently

accurate audiometry is obtained at three months, periodic follow-up audiometry is appropriate to confirm the

early measurements, to refine threshold estimates and to detect and quantify possible changes in hearing. In older

infants, the amplification audiologist will attempt VRA or CPA using insert earphones coupled to foam eartips. If

the child has personal earmolds, the insert earphones should be coupled to the earmolds to improve the likelihood

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that the phones will be retained in the child’s ear (see Appendix C for practical description). Any changes to the

infant’s auditory thresholds should be applied to the hearing instrument prescription as needed.

S2.2 ACOUSTIC CHARACTERISTICS

The acoustics of an infant’s external ears significantly differ from those of the average adult (Kruger, 1987). In

addition, RECD values are known to be highly variable among children of the same age (Feigin et al., 1989; Seewald

& Scollie, 1999; Bagatto et al, 2002; Bagatto et al, 2006). For these reasons, it is strongly recommended that

wherever feasible, IHP audiologists measure the individual infant’s RECD as part of the provision of amplification.

In the event that the individual measurement is unobtainable, age-related predicted values can be applied

(Bagatto et al, 2002).

When comparing audiometric thresholds for the same infant over time, it is important to take into account the

changes in individual ear-canal acoustics. RECD measurements shall be applied so that the thresholds are

represented in either real ear SPL or equivalent adult hearing level (sometimes called HLp), because both of these

scales allow appraisal of threshold changes independent of ear canal acoustic changes. For example, when

comparing VRA thresholds completed at 9 months of age to ABR threshold estimations collected at 3 months of

age, the RECD must be applied to both sets of thresholds to obtain an individualized and more accurate threshold

representation. If ear canal acoustics are not considered when making this comparison, what appears to be a

change in hearing threshold sensitivity may be a result of changes in ear canal acoustics due to ear growth. These

calculations are commonly automated in many commercial hearing aid analyzers.

S2.3 RECD MEASUREMENT

Briefly, the HA-2 coupler is connected to the coupler microphone of the unit and a transducer is coupled to the

other end of the HA-2 coupler. A swept-frequency stimulus generated by the probe microphone system is

delivered into the coupler and the coupler response is measured by the microphone. A foam eartip or personal

earmold is coupled to the transducer and inserted into the infant’s ear. It may be helpful to couple the probe tube

to an immittance or OAE tip with plastic wrap (i.e. moisture guard or soft surgical tape) for very small ear canals.

Ensure the probe tube extends approximately 2-4 mm past the opening of the tip to obtain appropriate insertion

depth (Bagatto et al, 2006). This technique is helpful in coordinating insertion and ensuring a constant length of

the probe tube remains at the tip edge. The same stimulus is presented via the probe microphone system and

insert earphone coupling, and the real-ear response is measured. The difference between the real-ear response

and the coupler response is obtained. This difference is the individual transfer function designated as the RECD and

will be applied throughout several stages of the amplification process.

S2.4 AGE-APPROPRIATE PREDICTED RECD VALUES

Using an age-appropriate predicted RECD value is more desirable than using an average adult value for infants.

However, age-appropriate average values in current use have some limitations. First, the average RECD values

were derived from infants and children with normal middle ear status. Therefore, the predicted values will not

reflect any acoustic changes that a fluid filled or perforated eardrum will display, in the individual ear. Second,

individual real-ear SPL values may differ substantially from group average values, even in age-matched groups.

When applying RECD predicted values for eartips, one can expect to fall within a range of ±5.6 dB (at 500 Hz) as

best and ±10.9 dB (at 6000 Hz) at worst for children 24 months of age and younger. Predictions of earmold RECDs

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can span a range of accuracy from ±6.7 dB (at 2000 Hz) to ±12.4 dB (at 6000 Hz) for children 36 months of age and

younger. An RECD measurement should therefore be attempted whenever possible. However, when these values

cannot be obtained, age-appropriate predicted values found in applications of DSL m[i/o] v5 should be applied.

SUPPLEMENT 3: PRESCIPTION OF AMPLIFICATION

S3.1 NON-ELECTROACOUSTIC CHARACTERISTICS

Behind-the-ear (BTE) hearing instruments are most appropriate for infants for several reasons:

1. Rapid growth of the earmold causes frequent remakes which are less costly and more convenient than

custom (i.e. in-the-ear, in-the-canal) hearing instruments

2. Custom products are more prone to feedback due to the close proximity of the receiver and microphone

3. BTEs allow for greater electroacoustic flexibility

4. Direct audio input capabilities are more compatible with the target population

5. During out-of-office repairs of the BTE, a similar instrument can be coupled to the child’s earmold so the

child is not without amplification.

Other types of personal amplification such as bone conduction hearing instruments on a soft headband, bone

anchored hearing instruments, and cochlear implants should also be considered on an individual basis. It is the

audiologist’s responsibility to inform families of these options and to ensure their knowledge of current referral

criteria.

Infants with confirmed PCHI in both ears shall be fitted with bilateral hearing instruments unless contraindicated.

Many studies have demonstrated the benefits of bilateral hearing (Hawkins & Yacullo, 1984; Valente, 1982a,

1982b). Additionally, auditory deprivation in children with unilateral amplification has been reported (Boothroyd,

1992; Hattori, 1993).

Direct audio input (DAI) shall be included on the selected devices. This will enable coupling of assistive technology,

such as FM systems, to the hearing instruments. Tamper resistant battery doors shall be included on hearing

instruments for infants. A deactivation or locking system for the volume control and other automatic features shall

be available on the hearing instruments.

While BTE hearing instruments may be the device of choice for infants with PCHI, some infants may have a

conductive hearing impairment caused by a structural issue (i.e. atresia, middle ear malformation). Since children

under the age of 5 years are not typically candidates for surgically implanted bone anchored hearing instruments,

bone conduction hearing instruments shall be considered. Traditional bone conduction instruments are kept in

place by a metal headband or two-sided tape. There are some disadvantages to this setup such as discomfort and

difficulty keeping the instrument in place. A bone anchored hearing instrument attached to a soft headband uses

an adjustable elastic headband to house the bone conduction processor and hold it in place on the infant’s head. It

has been demonstrated that the direct contact force of the bone conduction processor on the infant’s head does

not have a significant effect on audibility (Hodgetts et al, 2006). Therefore, a snug but comfortable setting of the

headband should be sufficient to couple the bone conduction instrument to the infant’s head. Data from adults

with normal hearing sensitivity indicate that a volume control setting of approximately three was closely

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associated with the preferred listening level. A volume control setting of at least 2.5 is therefore recommended for

a bone conduction hearing instrument on a headband, accompanied by validation via aided sound field thresholds

and parent interviews/feedback.

S3.2 ELECTROACOUSTIC CHARACTERISTICS

When prescribing amplification for an infant, the selection of electroacoustic characteristics shall include the

following:

1. Sufficient gain, level-dependent processing, and frequency shaping to allow the hearing aid to be adjusted

to a child’s individualized DSL v5 prescription using the procedures described in this document.

2. The hearing instrument(s) selected shall avoid unnecessary distortion.

3. The hearing instrument(s) selected shall provide electroacoustic flexibility to accommodate anticipated

changes in ear canal growth, changes in hearing threshold level if known or suspected, and anticipated

needs for coupling to external sound sources or for advanced signal processing.

S3.3 DEVICE SELECTION

Unless otherwise instructed, manufacturers may send adult-sized unfiltered earhooks when BTE hearing

instruments are ordered. A pediatric earhook will allow the BTE to stay situated on the infant’s ear. In addition,

unfiltered earhooks will add resonant peaks to the output response of the hearing instrument, possibly causing

feedback and making adjustment to MPO targets difficult. A filtered earhook will smooth the response and allow

for a better match to targets with less chance of feedback (Scollie & Seewald, 2002). Therefore, prescriptions

should specify filtered pediatric earhooks unless contraindicated.

S3.4 OTHER ASSISTIVE TECHNOLOGY

It has been well documented that the use of remote microphone hearing assistance technology by children in

educational settings is an effective strategy for improving listening in environments with poor signal to noise

ratios, great distance between listener and talker, and highly reverberant rooms (AAA, 2013). While a remote

microphone technology (FM/DM) system may not be used in the first few months of life, when the infant becomes

a toddler, more difficult listening situations will develop. The child may be at a distance from the primary caregiver

or talker and in highly reverberant environments. In addition, use of this technology may increase the rate of

language acquisition (Moeller et al, 1996). For these reasons, it is recommended that remote microphone hearing

assistance technologies be discussed with the family during amplification appointments and provided when

appropriate. Further information on selecting and verifying remote microphone hearing assistance technologies

can be found in Addendum 6.

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SUPPLEMENT 4: INFORMATION AND INSTRUCTION

S4.1 ORIENTATION

The dispenser will ensure that the following care and maintenance techniques are demonstrated to the parent or

caregiver during the initial hearing instrument orientation:

Demonstration of earmold insertion, including use of oto-ease and other practical fitting suggestions, such

as putting the hearing instruments on, etc.

Hands-on demonstration and practice of earmold insertion, tubing attachment to hearing instrument,

insertion of batteries, etc.

Demonstration of a daily inspection of ear canal, and daily listening check of the hearing instruments. The

listening check should include adjustment of controls, Ling 6 Sounds Check, etc.

Discussion and demonstration of troubleshooting techniques and solutions.

Demonstration of equipment found in the care and maintenance kit – battery tester, earmold blower,

stethoscope, dri-aid kit, etc.

Discussion of retention techniques – demonstration of critter clips, double-sided tape, huggie-aids, etc.

A complete list of discussion topics for clinicians and families is included in Appendix F.

The dispenser will also provide written information from the manufacturer for parents to take home and refer to,

and other appropriate Infant Hearing Program pamphlets and information.

SUPPLEMENT 5: OUTCOME EVALUATION

S5.1 OUTCOME MEASURES

At the follow-up visits, the audiologist should meet with the parent/caregiver to discuss satisfaction with the fit of

the hearing instruments and the infant’s performance with them. Since 2010, the IHP has implemented a

systematic, evidence-based Outcome Measurement Protocol for children who wear hearing aids. It consists of

caregiver questionnaires that assess auditory development (i.e., LittlEARS Auditory Questionnaire) and auditory

performance (i.e., Parents’ Evaluation of Aural/Oral Performance of Children [PEACH]) as well as a parental

satisfaction survey (i.e., IHP Amplification Benefit Questionnaire). In addition, tools to assess the quality of the

hearing aid fitting (i.e., Speech Intelligibility Index) are provided in order to support interpretation of functional

outcomes.

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SECTION 9: REFERENCES

ANSI (1996). American National Standard Specification for Audiometers (ANSI S3.6-1996). New York, American National Standard Institute. Bagatto, M., Moodie, S., Scollie, S., Seewald, R., Moodie, S., Pumford, J. & Liu, K.P. (2005). Clinical protocols for hearing instrument fitting in the Desired Sensation Level method, Trends in Amplification, 9(4), 199-226. Bagatto, M.P., Moodie, S.T., Malandrino, A.C., Richert, F.M., Clench, D.A. & Scollie, S.D. (2011). The University of Western Ontario Pediatric Audiological Monitoring Protocol (UWO PedAMP), Trends in Amplification, 15(1), 57-76. Bagatto, M.P., Scollie, S.D., Seewald, R.C. Moodie, K.S. & Hoover, B.M. (2002). Real-ear-to-coupler difference predictions as a function of age for two coupling procedures, Journal of the American Academy of Audiology, 13(8), 407-415. Bagatto, M.P., Seewald, R.C., Scollie, S.D. & Tharpe, A.M. (2006). Evaluation of a probe-tube insertion technique for measuring the real-ear-to-coupler difference (RECD) in young infants, Journal of the American Academy of Audiology, 17(8), 573-581. Bess, F.H., Dodd-Murphy, J. & Parker, R.A. (1998). Children with minimal sensorineural hearing loss: prevalence, educational performance, and functional status, Ear and Hearing, 19(5), 339-354. Bess, F.H. & Tharpe, A.M (1984). Unilateral hearing impairment in children, Pediatrics, 74(2), 206-216. Canadian Worki

Documents

Protocol for the Provision of Amplification · Audiology and Speech-Language Pathology Act, 1991. All services for Amplification funded by the IHP shall be conducted exclusively by